Rockbox mail archive
Subject: Re: firmware/serial.c mod problem. please help.Re: firmware/serial.c mod problem. please help.
- Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ] [ by messages with attachments ]
From: [IDC]Dragon <idc-dragon_at_gmx.de>
Date: Tue, 20 Apr 2004 11:47:32 +0200 (MEST)
> the idle serial level is 1, the start bit is 0...
> how are these serial level at the TTL side and in the RS232 side?
On TTL, 1 is high and 0 is low.
On RS232, 1 is -12V and 0 is +12V.
> are the RS232 levels inverted compared to TTL?
Yes.
> In my case, I connected the pic output directly to the serial Rx of my
> PC and it works.
This is strange. Maybe the PIC has an option to invert its TX?
> As the serial driver is in software, I dont remember the levels I used,
> but I think it is inverted.
Ah, that explains.
> Does this mean I need at least an inverter (or a rs232 adapter) for the
> archos to transmit to the PC?
Yes. As a minimum solution, a transistor can do it.
Jörg
Date: Tue, 20 Apr 2004 11:47:32 +0200 (MEST)
> the idle serial level is 1, the start bit is 0...
> how are these serial level at the TTL side and in the RS232 side?
On TTL, 1 is high and 0 is low.
On RS232, 1 is -12V and 0 is +12V.
> are the RS232 levels inverted compared to TTL?
Yes.
> In my case, I connected the pic output directly to the serial Rx of my
> PC and it works.
This is strange. Maybe the PIC has an option to invert its TX?
> As the serial driver is in software, I dont remember the levels I used,
> but I think it is inverted.
Ah, that explains.
> Does this mean I need at least an inverter (or a rs232 adapter) for the
> archos to transmit to the PC?
Yes. As a minimum solution, a transistor can do it.
Jörg
-- NEU : GMX Internet.FreeDSL Ab sofort DSL-Tarif ohne Grundgebühr: http://www.gmx.net/dsl _______________________________________________ http://cool.haxx.se/mailman/listinfo/rockboxReceived on 2004-04-20
Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy